The present invention relates to miniature probe technology for the measurement of electrical signals, and more particularly to a twist lock probe tip for use with a passive probe configured to provide a mechanism for anchoring the probe tip to the leads of a leaded integrated circuit package.
In the testing and troubleshooting of electrical equipment it is necessary to make electrical contact at many places on a circuit board, as well as to leads of various components on the circuit board such as integrated circuits. A common configuration for integrated circuits is a leaded package having leads closely spaced projecting from opposing parallel sides of the package. As the number of leads per package increases and the integrated circuit size decreases, the spacing between leads becomes very small, i.e., less than 100 mils. Current small probe tips either require the operator to hold the probe against the component's lead, or employ enough exposed metal so that there is significant risk of contacting two leads at the same time, electrically shorting one lead to the other with resulting damage to the component.
One example of the prior art probe tips is a grabber tip that has either a rigid or flexible insulated tube within which there is an electrical conductor. The electrical conductor has a hook at the end to "grab" an integrated circuit lead, and is spring biased to be retracted into the insulated tube. The hook is opened when the conductor is extended out of the tube under pressure, and then closes around the component lead when the pressure is released and the spring bias retracts the conductor back into the tube. However this configuration, although providing a means for anchoring the probe tip to the lead, has exposed metal that can short adjacent leads when attempting to connect the probe tip to the desired lead. For spacings of 50 mils or smaller the grabber tip becomes too awkward to use.
What is desired is a probe tip for small probes that may be anchored to contact a single lead of an integrated package without running the risk of shorting adjacent leads and that is usable with small lead spacings of 50 mils or less.